Rhode Island Fluke, on a bed of black squid ink quinoa, served with green and yellow squash and mint.

Once the customer was always right. Want your pork cooked well-done? Done. Want tomatoes in the dead of winter? The restaurant has to have them. Want your onion soup made without any actual onion? Yes, of course we can do that.

Until, one day, the customer became a little less right. We began to celebrate chefs, and chefs began to prize control from our high-maintenance little fingers, for our own good. I’m sorry, sir or madame, we cannot make that steak dish vegetarian for you. This restaurant only serves tomatoes in season. There is no salt on the table because the food is seasoned just right. Chef recommends eating the dishes in clockwise order. No substitutions. No photographs.

So which way should it be? Pull the issue taut like a rubber band on the fingertips, release it, and watch it fly. The debates are impassioned. Is food art, or is it commerce? Are paying customers entitled to what they want, anywhere, any time? Are chefs who take a stance arrogant or possessed of integrity?

Into the fray steps Jeffrey Fournier, chef-owner of 51 Lincoln and Waban Kitchen in Newton. In February he penned a new mission statement for the former, opened in 2006. In it, he commits firmly to the side of art (and in fact is a fine visual artist himself, the proof of which hangs on the restaurant’s walls). “I have always believed that — under the guidance of a dedicated and passionate team — food can be art, kitchens can be studios and restaurants can be galleries where patrons experience and appreciate the outcome of our creative efforts,” he writes. Yet trends, finances, and other factors often distract from that.

Factors like the pesky customer who thinks he or she is always right. “In the past, we have been constrained by appeasing diners who demand certain dishes despite seasonality. Our watermelon steak is the perfect example of a dish that began as a successful culinary invention and evolved into an obligation.” Going forward, this signature dish would only be available in summer when the watermelon is best. The menu would be smaller, reservations fewer, ingredients natural and sustainable. Dishes would only be changed to accommodate allergies.

Then there is the minestrone. When a chef takes an impassioned stand, it is not usually for the sake of soup. Perhaps this one is creatively reimagined, deconstructed? Are the beans actually “beans” — some sort of molecular gastronomy-fueled mind-bender? No. This is garden-variety minestrone, with kidney beans and ditalini. You might find a similar version at a nice diner. Would it have disappointed equally served at 51 Lincoln version 1.0? No again. With mission statements come expectations.

A dish of hanger steak sounds simple and clean. The meat is served with leek and garlic couscous, bean salad, yogurt dressing, and mint vinaigrette. But the steak is very overcooked, tough and dry.

Watermelon steak may be out of season, but cauliflower steak is on offer: a nicely browned, lightly caramelized cross-section of a purple head set against a creamy drift of pink smoked cauliflower puree. The plate is dusted with tiny, bright flowers, and a sort of dried fruit stuffing appears, sweet to my taste but offering some contrast to the vegetable. More contrast would be welcome — some acid, more salt. But the plate looks arresting, and the concept is interesting. (So is the $24 a la carte price tag. For cauliflower.)

Dina Rudick/Globe Staff

Peas and chickpeas with black olive orzo, spring garlic, pea shoots.

Rhode Island fluke is cooked nicely, golden and fresh, served with green and yellow squash and fresh mint. The fluke sits on a bed of black squid ink quinoa, a red chile sauce dotting the plate. Scattered over everything are kernels of dehydrated corn. Aside from this sweet Styrofoam, it is a well realized dish. So is an appetizer of seared chicken livers with polenta, Meyer lemon-ginger marmalade, smoked shallot rings, and Swiss chard.

The minestrone equivalent on the list of entrees is Fournier’s “famous” rigatoni Bolognese. (Have you heard of it?) It is another signature dish at 51 Lincoln, and perfectly in season. Bolognese is always tasty. But is it art?

Desserts incorporate more creativity — “lemon cream pie . . . ish” that features a lemon filled with lemon custard and topped with meringue, no crust; a grapefruit and pink peppercorn sorbet that only tastes like peppercorns, without any citrus flavor to balance it. It may be the first scoop of sorbet I’ve ever left nearly untouched.

The bar menu, on the other hand, offers an accessible mix — chicken empanadas one night, a burger, Miller High Life and Belgian beer. Combined with a fine selection of cheese and charcuterie, rotating wine specials and a thoughtfully selected roster of bottles, and a cocktail list replete with geeky invention (sarsaparilla tincture here, kumquat puree and warm spices there), it helps bring 51 Lincoln back into neighborhood restaurant territory, where it sits comfortably. Servers are sometimes quirky, knowledgeable, and funny, sometimes awkward — hovering one minute, disappearing the next.

Kudos to Fournier. To thine own self be true. Just make sure you keep the customers happy, too. Ideals don’t pay the bills.